Methods and systems for fault diagnosis

ABSTRACT

The present disclosure relates to a control system and methods implemented on the control system. The control system includes a tuning/detuning system and a diagnosis system. The tuning/detuning system includes a first voltage source, a second voltage source, one or more coil arrays, and one or more tuning/detuning circuit drivers corresponding to the one or more coils arrays, respectively. The diagnosis system includes a first current sampling circuit and a processor. The first current sampling circuit is configured to obtain a first current. The processor is configured to diagnose the tuning/detuning system based on the first current.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present disclosure is a continuation of U.S. patent application Ser.No. 16/023,128, filed on Jun. 29, 2018, which is a continuation ofinternational Application No. PCT/CN2017/120287, filed on Dec. 29, 2017,designating the United States of America, which claims priority ofChinese Application No. CN 201710674295.4 filed on Aug. 9, 2017, thecontent of which is hereby incorporated by reference in its entirety.

TECHNICAL FIELD

The present disclosure generally relates to methods and systems forfault diagnosis, and more particularly, to methods and systems for faultdiagnosis of a tuning/detuning system of local coils in a magneticresonance imaging (MRI) system.

BACKGROUND

Local coils are widely used in an MRI system. The local coils mayinclude a variety of types, for example, abdomen coils, head coils.Local coil may be configured as one or more coil arrays, each of whichmay include one or more coil elements. A coil element may include one ormore diodes, capacitors, inductors, etc. A tuning/detuning system may beused to control the local coils, referred to as tuning control anddetuning control. The tuning control refers to making the diodesconduct, and the detuning control refers to making the diodes notconduct. In practice, fault diagnosis for the tuning/detuning system isneeded.

SUMMARY

According to an aspect of the present disclosure, a control system mayinclude a tuning/detuning system and a diagnosis system. Thetuning/detuning system may include a first voltage source, a secondvoltage source, one or more coil arrays, and one or more tuning/detuningcircuit drivers corresponding to the one or more coils arrays,respectively. The first voltage source, including a first output end,may be configured to provide a power supply that outputs a constantcurrent. The second voltage source, including a second output end, maybe configured to output a constant negative voltage. For each of the oneor more coil arrays, the coil array may include one or more firstdiodes. The one or more first diodes may determine a tuning or detuningstatus of the coil array. For each of the one or more tuning/detuningcircuit drivers, the tuning/detuning circuit may include a first inputend, a second input end, a third output end, and a first control end.The first input end, electrically connected to the first output end ofthe first voltage source, may serve as a positive power supply inputport and may be configured to output the constant current. The secondinput end, electrically connected to the second output end of the secondvoltage source, may serve as a negative power supply input port and maybe configured to output the constant negative voltage. The third outputend, electrically connected to a corresponding coil array, may beconfigured to output the constant current or the constant negativevoltage that determines a conduction status of the one or more firstdiodes of the corresponding coil array. The diagnosis system may includea first current sampling circuit and a processor. The first currentsampling circuit, including a fourth output end, may be configured toobtain a first current of the first output end. The processor,operatively connected to the fourth output end and at least one of theone or more first control ends, may be configured to determine the firstinput end or the second input end to be electrically connected to thethird output end and to diagnose the tuning/detuning system based on thefirst current of the first output end

In some embodiments, the first current sampling circuit may include afirst analog-to-digital converter (ADC), a first operational amplifier,and a first sampling resistor. The first ADC may be electricallyconnected to the first operational amplifier in series and operativelyconnected to the processor. The first operational amplifier may beelectrically connected to the first sampling resistor in parallel. Thefirst sampling resistor may be electrically connected to the firstvoltage source in series and electrically connected to at least one ofthe one or more tuning/detuning circuit drivers in series.

In some embodiments, the diagnosis circuit system may include a firstswitch module and one or more dummy loads corresponding to the one ormore tuning/detuning circuit drivers. Each dummy load of the one or moredummy loads, including one or more second diodes, may be electricallyconnected to a corresponding tuning/detuning circuit in parallel. Theone or more dummy loads may be electrically connected to a commonconnecting end in parallel. The first switch module may be electricallyconnected to ground, electrically connected to the common connectingend, and operatively connected to the processor. The processor may beconfigured to cause the first switch module to turn on or turn off, andto diagnose the tuning/detuning system based on the first current.

In some embodiments, the diagnosis circuit system may include a secondcurrent sampling circuit. The second current sampling circuit,operatively connected to the processor, may be configured to obtain asecond current of the common connecting end. The processor may beconfigured to diagnose the tuning/detuning system based on the secondcurrent.

In some embodiments, the second current sampling circuit may include asecond ADC, a second operational amplifier, and a second resistor. Thesecond ADC may be electrically connected to the second operationalamplifier in series and operatively connected to the processor. Thesecond operational amplifier may be electrically connected to the secondresistor in parallel. The second resistor may be electrically connectedto the first switch module in series and electrically connected to atleast one of the one or more dummy loads in series.

In some embodiments, the diagnosis circuit system may include a thirdresistor, a second switch module, and a voltage comparison circuit. Thethird resistor may be electrically connected to the second switch modulein parallel. A first end of the third resistor may be electricallyconnected to the second voltage source. A second end of the thirdresistor may be electrically connected to at least one of the one ormore tuning/detuning circuit drivers. The voltage comparison circuit maybe electrically connected to the second end of the third resistor andoperatively connected to the processor. The voltage comparison circuitmay be configured to obtain a first voltage of the second end of thethird resistor and compare the first voltage with a reference voltage.The processor may be configured to diagnose the tuning/detuning systembased on the comparison between the first voltage and the referencevoltage.

In some embodiments, the diagnosis circuit system may include a thirdswitch module. The third switch module may be electrically connected tothe second voltage source in series, electrically connected to the thirdresistor in series, and operatively connected to the processor. Theprocessor may be configured to cause the third switch module to turn onor turn off.

In some embodiments, the first voltage source may include a DC-DCcontroller, a fourth resistor, and a variable resistor. The DC-DCcontroller may be electrically connected to the first output end of thefirst voltage source though an output end of the DC-DC controller. Thefourth resistor may be electrically connected to ground and electricallyconnected to the DC-DC controller through a feedback input of the DC-DCcontroller. The variable resistor may be electrically connected to thefourth resistor, electrically connected to the first output end of thefirst voltage source, and operatively connected to the processor. Theprocessor may be configured to cause an equivalent resistance value ofthe variable resistor to change.

According to an aspect of the present disclosure, a method implementedon the control system may include determining, by the diagnosis circuitsystem, an expected value of an electrical signal according to at leastone of an operation status of a radio frequency system, a tuning ordetuning status of the one or more coil arrays, and types of voltagesources of the one or more tuning/detuning circuit drivers; obtaining afirst actual value of the electrical signal; and performing, by thediagnosis circuit system, fault diagnosis on the tuning/detuning systembased on the expected value of the electrical signal and the firstactual value of the electrical signal.

In some embodiments, the determining the expected value of theelectrical signal may include upon a detection that the radio frequencysystem is idle and the one or more coil arrays may be electricallyconnected to the radio frequency system, making the second voltagesource as the voltage source of the one or more tuning/detuning circuitdrivers. The performing fault diagnosis on the tuning/detuning systemmay include determining whether the first actual value of the firstcurrent falls within the first expected range of the first current.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include determining that the firstactual value of the first current falls within the first expected rangeof the first current; and in response to a determination that the firstactual value of the first current falls within the first expected rangeof the first current, determining that no short circuit exists at theone or more first input ends of the one or more tuning/detuning circuitdrivers.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include determining that the firstactual value of the first current fails to fall within the firstexpected range of the first current; and in response to a determinationthat the first actual value of the first current fails to fall withinthe first expected range of the first current, determining that a shortcircuit exists at at least one of the one or more first input ends ofthe one or more tuning/detuning circuit drivers.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include changing a type of thevoltage source of one of the one or more tuning/detuning circuit driversto the first voltage source; obtaining a second actual value of thefirst current; and determining whether the second actual value of thefirst current increases by a predetermined increment.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include determining that the secondactual value of the first current increases by a predeterminedincrement; and in response to a determination that the second actualvalue of the first current increases by the predetermined increment,determining that the tuning/detuning circuit driver and a correspondingcoil array are normal.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include determining that the secondactual value of the first current fails to increase by a predeterminedincrement; and in response to a determination that the second actualvalue of the first current fails to increase by the predeterminedincrement, determining that an open circuit exists in thetuning/detuning circuit driver or a corresponding coil array.

In some embodiments, the determining the expected value of theelectrical signal may include upon a detection that the radio frequencysystem is performing a scan and the one or more coil arrays may beelectrically connected to the radio frequency system, determining asecond expected range of the first current according to the number ofcoil arrays whose voltage source is the first voltage source. Theperforming fault diagnosis on the tuning/detuning system may includedetermining whether the first actual value of the first current fallswithin the second expected range of the first current.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include determining that the firstactual value of the first current falls within the second expected rangeof the first current; and in response to a determination that the firstactual value of the first current falls within the second expected rangeof the first current, determining that the one or more tuning/detuningcircuit drivers and the one or more coil arrays are normal.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include determining that the firstactual value of the first current is lower than a lower limit of thesecond expected range of the first current; and in response to adetermination that the first actual value of the first current is lowerthan the lower limit of the second expected range of the first current,determining that an open circuit exists in at least one of the one ormore tuning/detuning circuit drivers or the one or more coil arrays.

In some embodiments, the performing fault diagnosis on thetuning/detuning system may further include determining that the actualvalue of the first current is greater than an upper limit of the secondexpected range of the first current; and in response to a determinationthat the actual value of the first current is greater than the upperlimit of the second expected range of the first current, determiningthat a short circuit exists in at least one of the one or moretuning/detuning circuit drivers or the one or more coil arrays.

In some embodiments, the method may further include changing a type ofthe voltage source of one of the one or more tuning/detuning circuitdrivers; determining a second actual value of the first current; anddetermining whether the second actual value of the first currentincreases or decreases by a predetermined increment.

In some embodiments, the method may further include determining that thesecond actual value of the first current increases or decreases by thepredetermined increment; and in response to a determination that thesecond actual value of the first current increases or decreases by thepredetermined increment, determining that the tuning/detuning circuitdriver and a corresponding coil array are normal.

In some embodiments, the method may further include determining that thesecond actual value of the first current fails to increase or decreaseby the predetermined increment; and in response to a determination thatthe second actual value of the first current fails to increase ordecrease by the predetermined increment, determining that an opencircuit exists in tuning/detuning circuit driver or a corresponding coilarray.

In some embodiments, the method may further include upon a detectionthat the radio frequency system is idle and the one or more coil arraysare electrically disconnected from the radio frequency system, makingthe second voltage source as the voltage source of the one or moretuning/detuning circuit drivers, and determining a third expected rangeof the first current; determining a first actual value of the firstcurrent; and determining whether the first actual value of the firstcurrent falls within the third expected range of the first current.

In some embodiments, the method may further include determining that thefirst actual value of the first current falls within the third expectedrange of the first current; and in response to a determination that thefirst actual value of the first current falls within the third expectedrange of the first current, determining that no short circuit exists atthe one or more first input ends of the one or more tuning/detuningcircuit drivers.

In some embodiments, the method may further include determining that thefirst actual value of the first current fails to fall within the thirdexpected range of the first current; and in response to a determinationthat the actual value of the first current fails to fall within thethird expected range of the first current, determining that a shortcircuit exists at at least one of the one or more first input ends ofthe one or more tuning/detuning circuit drivers.

In some embodiments, the method may further include changing a type ofthe voltage source of one of the one or more tuning/detuning circuitdrivers to the first voltage source; determining a second actual valueof the first current; and determining whether the second actual value ofthe first current increases by a predetermined increment.

In some embodiments, the method may further include determining that thesecond actual value of the first current increases by the predeterminedincrement; and in response to a determination that the second actualvalue of the first current increases by the predetermined increment,determining that no short circuit exists at the first input end of thetuning/detuning circuit driver.

In some embodiments, the method may further include determining that thesecond actual value of the first current fails to increase by thepredetermined increment; and in response to a determination that theactual value of the first current fails to increase by the predeterminedincrement, determining that a short circuit exists at the first inputend of the tuning/detuning circuit driver.

In some embodiments, the method may further include changing a type ofthe voltage source of one of the one or more tuning/detuning circuitdrivers to the first voltage source; determining a second actual valueof the first current; and determining whether the second actual value ofthe first current increases by a predetermined increment.

In some embodiments, the method may further include determining that thesecond actual value of the first current fails to increase by thepredetermined increment; and in response to a determination that thesecond actual value of the first current fails to increase by thepredetermined increment, determining that an open circuit exists in thetuning/detuning circuit driver.

In some embodiments, the method may further include determining that thesecond actual value of the first current increases by the predeterminedincrement; in response to a determination that the second actual valueof the first current increases by the predetermined increment,determining an actual value of the second current; and determiningwhether the actual value of the second current increases by thepredetermined increment.

In some embodiments, the method may further include determining that theactual value of the second current increases by the predeterminedincrement; and in response to a determination that the actual value ofthe second current increases by the predetermined increment, determiningthat no short circuit exists at the third output end of thetuning/detuning circuit driver.

In some embodiments, the method may further include determining that theactual value of the second current fails to increase by thepredetermined increment; and in response to a determination that theactual value of the second current fails to increase by thepredetermined increment, determining that a short circuit exists at thethird output end of the tuning/detuning circuit driver.

According to an aspect of the present disclosure, a method implementedon the control system may include upon a detection that a radiofrequency system is idle and the one or more coil arrays may beelectrically connected to the radio frequency system, making the secondvoltage source as the voltage source of the one or more tuning/detuningcircuit drivers and determining a first expected value of a firstvoltage; determining an actual value of the first voltage; anddetermining whether the actual value of the first voltage is greaterthan the first expected value of the first voltage.

In some embodiments, the method may further include determining that theactual value of the first voltage is greater than the first expectedvalue of the first voltage; and in response to a determination that theactual value of the first voltage is greater than the first expectedvalue of the first voltage, determining that no short circuit exists inthe one or more tuning/detuning circuit drivers and the one or more coilarrays.

In some embodiments, the method may further include determining that theactual value of the first voltage is not greater than the first expectedvalue of the first voltage; and in response to a determination that theactual value of the first voltage is not greater than the first expectedvalue of the first voltage, determining that a short circuit exists inat least one of the one or more tuning/detuning circuit drivers or theone or more coil arrays.

According to an aspect of the present disclosure, a method implementedon the control system may include upon a detection that a radiofrequency system is idle and the one or more coil arrays areelectrically disconnected from the radio frequency system, making thesecond voltage source as the voltage source of the one or moretuning/detuning circuit drivers and determining a second expected valueof a first voltage; determining an actual value of the first voltage;and determining whether the actual value of the first voltage is greaterthan the second expected value of the first voltage.

In some embodiments, the method may further include determining that theactual value of the first voltage is greater than the second expectedvalue of the first voltage; and in response to a determination that theactual value of the first voltage is greater than the second expectedvalue of the first voltage, determining that no short circuit exists inthe one or more tuning/detuning circuit driver.

In some embodiments, the method may further include determining that theactual value of the first voltage is not greater than the secondexpected value of the first voltage; and in response to a determinationthat the actual value of the first voltage is not greater than thesecond expected value of the first voltage, determining that a shortcircuit exists in at least one of the one or more tuning/detuningcircuit drivers.

According to an aspect of the present disclosure, a method implementedon the control system may include upon a detection that the firstvoltage source as voltage source of the one or more tuning/detuningcircuit drivers, determining an output voltage of the first voltagesource according to configurations of the one or more coil arrays;determining an expected value of an electrical signal according to atleast one of an operation status of a radio frequency system, a tuningor detuning status of the one or more coil arrays, and types of voltagesources of the one or more tuning/detuning circuit drivers; determiningan actual value of the electrical signal; and performing fault diagnosison the tuning/detuning system based on the expected value of theelectrical signal and the actual value of the electrical signal.

Additional features will be set forth in part in the description whichfollows, and in part will become apparent to those skilled in the artupon examination of the following and the accompanying drawings or maybe learned by production or operation of the examples. The features ofthe present disclosure may be realized and attained by practice or useof various aspects of the methodologies, instrumentalities andcombinations set forth in the detailed examples discussed below.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure is further described in terms of exemplaryembodiments. These exemplary embodiments are described in detail withreference to the drawings. These embodiments are non-limiting exemplaryembodiments, in which like reference numerals represent similarstructures throughout the several views of the drawings, and wherein:

FIG. 1 illustrates an exemplary magnetic resonance imaging system 100according to some embodiments of the present disclosure;

FIG. 2 illustrates an exemplary control system including a faultdiagnosis circuit system for a tuning/detuning system according to someembodiments of the present disclosure;

FIG. 3 illustrates an exemplary control system including a faultdiagnosis circuit system for a tuning/detuning system according to someembodiments of the present disclosure;

FIG. 4 illustrates an exemplary control system including a faultdiagnosis circuit system for a tuning/detuning system according to someembodiments of the present disclosure;

FIG. 5 illustrates an exemplary first voltage source according to someembodiments of the present disclosure;

FIG. 6 illustrates an exemplary process for fault diagnosis of atuning/detuning system according to some embodiments of the presentdisclosure;

FIG. 7 illustrates an exemplary process for current based faultdiagnosis of a tuning/detuning system based on a first current accordingto some embodiments of the present disclosure;

FIG. 8 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the change of a first current accordingto some embodiments of the present disclosure;

FIG. 9 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on a first current according to someembodiments of the present disclosure;

FIG. 10 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on a first current according to someembodiments of the present disclosure;

FIG. 11 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the change of a first current and asecond current according to some embodiments of the present disclosure;

FIG. 12 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on a first voltage according to someembodiments of the present disclosure;

FIG. 13 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on a first voltage according to someembodiments of the present disclosure; and

FIG. 14 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the electrical signal according to someembodiments of the present disclosure.

DETAILED DESCRIPTION

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant disclosure. However, it should be apparent to those skilledin the art that the present disclosure may be practiced without suchdetails. In other instances, well known methods, procedures, systems,components, and/or circuitry have been described at a relativelyhigh-level, without detail, in order to avoid unnecessarily obscuringaspects of the present disclosure. Various modifications to thedisclosed embodiments will be readily apparent to those skilled in theart, and the general principles defined herein may be applied to otherembodiments and applications without departing from the spirits andscope of the present disclosure. Thus, the present disclosure is notlimited to the embodiments shown, but to be accorded the widest scopeconsistent with the claims.

It will be understood that the term “system,” “module,” “unit,” and/or“block” used herein are one method to distinguish different components,elements, parts, section or assembly of different level in descendingorder. However, the terms may be displaced by another expression if theymay achieve the same purpose.

It will be understood that when a unit, module or block is referred toas being “on,” “connected to” or “coupled to” another unit, module, orblock, it may be directly on, connected or coupled to the other unit,module, or block, or intervening unit, module, or block may be present,unless the context clearly indicates otherwise. As used herein, the term“and/or” includes any and all combinations of one or more of theassociated listed items.

The terminology used herein is for the purposes of describing particularexamples and embodiments only, and is not intended to be limiting. Asused herein, the singular forms “a,” “an,” and “the” may be intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “include,”and/or “comprise,” when used in this disclosure, specify the presence ofintegers, devices, behaviors, stated features, steps, elements,operations, and/or components, but do not exclude the presence oraddition of one or more other integers, devices, behaviors, features,steps, elements, operations, components, and/or groups thereof.

The control system in the present disclosure is described primarily inregard to a diagnosis circuit system that may be used to diagnose atuning/detuning system of local coils of an MRI system. Based on thediagnosis circuit system, a method is provided to diagnose thetuning/detuning system. According to the method, an expected value of anelectrical signal of a sampling circuit may be determined according tothe operation status of a radio frequency (RF) system, the tuning ordetuning status of local coils, and types of voltage sources; an actualvalue of the electrical signal may be determined; and fault diagnosis ofthe tuning/detuning system may be performed based on the expected valueof the electrical signal and the actual value of the electrical signal.

FIG. 1 illustrates an exemplary magnetic resonance imaging systemaccording to some embodiments of the present disclosure. As illustrated,an MRI system 100 may include an MRI scanner 110, a control system 120,a processing system 130, and a user interface system 140. The MRIscanner 110 may include a magnet system 111 and a radio frequency (RF)system 112.

The magnet system 111 may include a main magnetic field generator and/ora gradient magnetic field generator (not shown in FIG. 1). The mainmagnetic field generator may include a main magnet that creates a staticmagnetic field B₀ during an MRI process. The main magnet may be ofvarious types including, for example, a permanent magnet, asuperconducting electromagnet, a resistive electromagnet, etc. Thegradient magnetic field generator may generate magnetic field gradientsin the X, Y, and/or Z directions. As used herein, the X direction isalso referred to as the readout (RO) direction, the Y direction is alsoreferred to the phase encoding (PE) direction, the Z direction is alsoreferred to the slice-select (SS) direction. The gradient magnetic fieldmay encode the spatial information of a subject (to be examined) locatedin the MRI scanner 110.

The RF system 112 may include RF transmitting coils and/or receivingcoils. The transmitting coils may transmit RF pulses to excite a regionof interest of the subject. Then the region of interest may generateecho signals. The receiving coils may receive the echo signals. In someembodiments, according to the difference in function and size, the RFcoils may be classified as volume coils and local coils. The volumecoils may be configured as birdcage coils, transverse electromagneticcoils, saddle coils, Helmholtz coils, etc. The local coils may includephased head coils, abdomen coils, etc.

The control system 120 may control the magnet system 111, the RF system112 of the MRI scanner 110, the processing system 130, and/or the userinterface system 140. The control system 120 may receive informationfrom or send information to the MRI scanner 110, the processing system130, and/or the user interface system 140. According to some embodimentsof the present disclosure, the control system 120 may receive commandsfrom the user interface system 140 provided by, e.g., a user, and causethe magnet system 111 and/or RF system 112 to image a region of interestaccording to the received commands. According to some embodiments of thepresent disclosure, the control system 120 may include a tuning/detuningsystem of the local coils of the RF system 112, and a diagnosis circuitsystem for diagnosing the tuning/detuning system. Descriptions regardingthe control system 120 may be found elsewhere in the present disclosure.See, e.g., FIGS. 2 to 6 and the descriptions thereof.

In some embodiments, the control system 120 may include one or moreprocessing units (e.g., single-core processor(s) or multi-coreprocessor(s)). Merely by way of example, the processing system 130 mayinclude a central processing unit (CPU), an application-specificintegrated circuit (ASIC), an application-specific instruction-setprocessor (ASIP), a graphics processing unit (GPU), a physics processingunit (PPU), a digital signal processor (DSP), a field programmable gatearray (FPGA), a programmable logic device (PLD), a controller, amicrocontroller unit, a reduced instruction-set computer (RISC), amicroprocessor, or the like, or any combination thereof.

The processing system 130 may process different kinds of informationreceived from different systems. In some embodiments, the processingsystem 130 may include one or more processing units. The one or moreprocessing units may be the same as or different from the one or moreprocessing units included in the control system 120.

For further understanding the present disclosure, several examples aregiven below, but the examples do not limit the scope of the presentdisclosure. For example, in some embodiments, the processing system 130may process MR signals received from the RF system 112 and generate oneor more MR images based on the MR signals and deliver the one or more MRimages to the user interface system 140 to be displayed, output forstorage or transmission to a terminal, etc. In some embodiments, theprocessing system 130 may process data input by a user (e.g., anoperator) via the user interface system 140, transform the data intospecific commands, and supply the commands to the control system 120. Insome embodiments, the processing system 130 may process imaging dataacquired by the MRI scanner 110 to generate images.

The user interface system 140 may receive input and/or display outputinformation. The input and/or output information may include programs,software, algorithms, data, text, number, images, voice, or the like, orany combination thereof. For example, a user may input one or moreinitial parameters or conditions to initiate a scan. As another example,some information may be imported from an external resource, such as afloppy disk, a hard disk, a wireless terminal, or the like, or anycombination thereof. In some embodiments, the user interface system 140may include an input device and/or a display device. The input devicemay include a keyboard, a touch screen, a mouse, a remote controller, orthe like, or any combination thereof. The display device may includeliquid crystal display (LCD), a light-emitting diode (LED)-baseddisplay, a flat panel display, a curved screen, a television device, acathode ray tube (CRT), a touch screen, or the like, or a combinationthereof. In some embodiments, the input device and the display devicemay be an integrated device that has both input and display functions.

In some embodiments, the control system 120, the processing system 130,and/or the user interface system 140 may be integrated into an MRIconsole. An operator may set parameters in MRI scanning, control theimaging procedure, view the images produced through the MRI console.

It should be noted that the above description of the MRI system 100 ismerely provided for the purposes of illustration, and not intended tolimit the scope of the present disclosure. For persons having ordinaryskills in the art, multiple variations and modifications may be madeunder the teachings of the present disclosure. For example, the assemblyand/or function of the MRI system 100 may be varied or changed accordingto specific implementation scenarios. Merely by way of example, someother components may be added into the MRI system 100, such as a patientpositioning module, a gradient amplifier module, and other devices ormodules. The MRI system may be a single-modality medical system, or partof a multi-modality system including, e.g., a positron emissiontomography-magnetic resonance imaging (PET-MRI) system, etc. However,those variations and modifications do not depart from the scope of thepresent disclosure.

FIG. 2 illustrates an exemplary control system 120 including a faultdiagnosis circuit system for a tuning/detuning system according to someembodiments of the present disclosure. The exemplary control system 120as illustrated in FIG. 2 may include a tuning/detuning system and afault diagnosis circuit system. The tuning/detuning system may include afirst voltage source 210, a second voltage source 220, local coils, andone or more tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n.The fault diagnosis circuit system may include a current samplingcircuit 131 and a processor 132.

The first voltage source 210 may be configured to provide a power supplyof a constant—current source (not shown in FIG. 2). Thus, theconstant-current source may be configured to output a constant current.In the present disclosure, for brevity, the first voltage source 210 mayserve as the constant-current source configured to output a constantcurrent. FIG. 5 illustrates an example of the first voltage source 210.The second voltage source 220 may be configured to output a constantnegative voltage through an output end Vcc2.

The local coils may include one or more coil arrays 290-1, 290-2, . . ., 290-n. In some embodiments, a coil array (e.g., 290-1, 290-2, 290-n)may correspond to a tuning/detuning circuit drivers (e.g., 280-1, 280-2,. . . , 280-n). A coil array (e.g., 290-1, 290-2, 290-n) may beelectrically connected to the corresponding tuning/detuning circuitdriver in series. For example, the coil array 290-1 may be electricallyconnected to the tuning/detuning circuit driver 280-1 in series. Asanother example, the coil array 290-2 may be electrically connected tothe tuning/detuning circuit driver 280-2 in series. As still anotherexample, the coil array 290-n may be electrically connected to thetuning/detuning circuit driver 280-n in series.

A coil array (e.g., 290-1, 290-2, . . . , 290-n) may include one or morecoil elements. The coil elements of a coil array may be electricallyconnected in series or in parallel. A coil element may include one ormore diodes D1 (for example, a PIN diode). The diodes D1 of a coilelement may be electrically connected in series or parallel. The one ormore diodes D1 may conduct or not conduct. When all of the one or morediodes D1 conduct, the coil element may be in a detuning state. Further,when all of the one or more coil elements in a coil array are in thedetuning state, the coil array may be in the detuning state accordingly.When all of the one or more diodes D1 do not conduct, the coil elementmay be in a tuning state. Further, when all of the one or more coilelements in a coil array are in the tuning state, the coil array may bein the tuning state accordingly. It should be noted that different coilelements may also be electrically connected in series or parallel.Different coil elements may include the same or different numbers ofdiodes D1.

Each of the one or more coil arrays 290-1, 290-2, . . . , 290-n may beof a configuration. The configuration of a coil array may relate to thenumber of diodes D1 and the connection between the diodes D1 of the coilarray. For brevity, the configuration of the coil array may be presentedby i*j. The i*j coil array may refer to a coil array including i*jdiodes Dl. For an i*j coil array, every i diodes D1 may be electricallyconnected in series, forming a series branch; the coil array may includej series branches. The j series branches may be electrically connectedin parallel. Each of i and j are an integral number more than zero.Merely by way of example, the configuration of the coil array mayinclude 3*4, 4*5, 5*2, etc. It should be noted that the configurationsof the coil arrays 290-1, 290-2, . . . , 290-n may be the same ordifferent. For example, the local coils may include 11 coil arrays and21 coil arrays.

A tuning/detuning circuit driver (e.g., 280-1, 280-2, . . . , 280-n) maybe configured to drive a coil array (e.g., 290-1, 290-2, . . . , 290-n).A tuning/detuning circuit driver (e.g., 280-1, 280-2, . . . , 280-n) mayinclude an input end In1, an input end In2, a control end Ctrl1, and anoutput end Out1. The input end In1 may be electrically connected to theoutput end Vcc1 of the first voltage source 210. The input end In1 mayserve as a positive power supply input port. When the input end In1 isan input end of the tuning/detuning circuit driver, the tuning/detuningcircuit driver may be configured to output a constant current. The inputend In2 may be electrically connected to the output end Vcc2 of thesecond voltage source 220. The input end In2 may serve as a negativepower supply input port. When the input end In2 is an input end of thetuning/detuning circuit driver, the tuning/detuning circuit driver maybe configured to output a constant negative voltage. The control endCtrl1 may be configured to receive commands indicating whether to selectthe input end In1 or the input end In2 as the input end of thetuning/detuning system. The commands may be transmitted from theprocessor 132.

The current sampling circuit 131 may be configured to sample a firstcurrent. The first current may refer to a current outputted by theconstant-current source provided by the first voltage source 210 and/ora current between the first voltage source 210 and a tuning/detuningcircuit driver (e.g., 280-1, 280-2, . . . , 280-n). The first currentmay be digitalized, for example, using an analog-to-digital converter(ADC) of the first current sampling circuit 131, which is exemplifiedbelow. The current sampling circuit 131 may sample an actual value ofthe first current and output the actual value of the first current tothe processor 132 through the Out2.

The processor 132 may be configured to command the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n. Forexample, the processor 132 may cause a tuning/detuning circuit driver toselect the first input end In1 as the input end through the control endCtrl1. In other words, the processor 132 may be configured to select thefirst voltage source 210 as the voltage source of the corresponding coilarray. As another example, the processor 132 may cause a tuning/detuningcircuit driver to select the second input end In2 as the input endthrough the control end Ctrl1. In other words, the processor 132 may beconfigured to select the second voltage source 220 as the voltage sourceof the corresponding coil array.

The processor 132 may further be configured to perform fault diagnosisof the tuning/detuning system. In some embodiments, the processor 132may perform the fault diagnosis based on an electrical signal acquiredby a sampling circuit. For example, the processor 132 may obtain anactual value and an expected value of the electrical signal. Further,the processor 132 may perform the fault diagnosis based on the actualvalue and the expected value of the electrical signal. The samplingcircuit may refer to a current sampling circuit, a voltage comparisoncircuit, etc. The electrical signal of the sampling circuit may includea current (e.g., the first current, the second current), a voltage, orthe like, or a combination thereof. In some embodiments, the processor132 may perform the fault diagnosis as descriptions in connection withFIGS. 6 to 14.

To facilitate the description of the tuning/detuning system and thefault diagnosis circuit system in the present disclosure, moredescriptions may be illustrated below. As illustrated in FIG. 2, thepositive end of one end diode D1 may be electrically connected to theoutput end Out1 and the negative end of the other end diode D1 may beelectrically connected to the ground. In some embodiments, if theprocessor 132 selects the first voltage source 210 as the voltage sourceof the tuning/detuning circuit driver, i.e., the processor 132 causesthe tuning/detuning circuit driver to select the input end In1 as theinput end of the tuning/detuning circuit driver through the control endCtrl1, the output end Out1 may output a constant current to thecorresponding coil array. In these embodiments, the diodes D1 in thecorresponding coil array may conduct, meaning that the correspondingcoil array is in the detuning state. Thus, a current passing through thecorresponding coil array may be the same or substantially the same asthe constant current. Accordingly, an expected value of a currentpassing through the output end Vcc1 (i.e., the first current describedin the present disclosure) may be determined based on the number of coilarrays or dummy loads (see, e.g., FIG. 3) whose voltage source is thefirst voltage source 210, as illustrated below:

I ₁ =I _(c) ×m,  (1)

where I₁ may refer to the expected value of the first current, I_(c) mayrefer to the constant current, and m may refer to the number of coilarrays or dummy loads whose voltage source is the first voltage source210.

For example, if the voltage source of the total coil arrays (i.e., allof the one or more coil arrays 290-1, 290-2, . . . , 290-n) is the firstvoltage source 210, m is n. Then, the expected value of the firstcurrent may be or approximately be I_(C)*n. As another example, if thevoltage source of the total coil arrays (i.e., all of the one or morecoil arrays 290-1, 290-2, . . . , 290-n) is the second voltage source220, m is 0. Then, the expected value of the first current may be zeroor approximately zero. It should be noted that when the voltage sourceof an additional coil array is changed to the first voltage source 210,the first current may increase by an increment. The increment may be thesame as or substantially the same as I_(C).

An expected value of an electrical signal (e.g., the first current, thesecond current) acquired by a sampling circuit may refer to a value ofthe electrical signal when the tuning/detuning system is normal. Theexpected value of an electrical signal may be calculated or measured.

FIG. 3 illustrates an exemplary control system 120 including a faultdiagnosis circuit system for a tuning/detuning system according to someembodiments of the present disclosure. The exemplary control system 120as illustrated in FIG. 3 may include the first voltage source 210, thesecond voltage source 220, the processor 132, the first current samplingcircuit 131, the one or more tuning/detuning circuit driver 280-1,280-2, . . . , 280-n, and the one or more coil array 290-1, 290-2, . . ., 290-n, similar to those illustrated in FIG. 2, the descriptions ofwhich are not repeated here. Further, the exemplary control system 120as illustrated in FIG. 3 may include one or more dummy loads 133-1,133-2, . . . , 133-n, a first switch module 134, and a second currentsampling circuit 135.

A dummy load (e.g., 133-1, 133-2, . . . , 133-n) may correspond to atuning/detuning circuit driver (e.g., 280-1, 280-2, . . . , 280-n). Adummy load (e.g., 133-1, 133-2, . . . , 133-n) may correspond to a coilarray (e.g., 290-1, 290-2, . . . , 290-n). One end of a dummy load maybe electrically connected to the output end Out1 of the correspondingtuning/detuning circuit driver. The other end of the dummy load may beelectrically connected to a common connecting end to a first switchmodule 134. A dummy load (e.g., 133-1, 133-2, . . . , 133-n) may includeone or more diodes D2. For simplicity, only one diode D2 is illustratedonly in the dummy load 133-1. It is understood that other dummy loads133-2, . . . , 133-n, as well as the dummy load 133-1, may also includeone or more diodes D2. One end of the one or more diodes D2 may beelectrically connected to the output end Out1 of the correspondingtuning/detuning circuit driver. The other end of the one or more diodesD2 may be electrically connected to the common connecting end to thefirst switch module 134.

The first switch module 134 may include a first end, a second end, and acontrol end Ctrl2. The first end may be electrically connected to thecommon connecting end of the dummy loads. The second end may beelectrically connected to the ground. The control end Ctrl2 may beoperatively connected to the processor 132. In some embodiments, thefirst switch module 134 may be a switch, a relay, or the like, or thecombination thereof.

Accordingly, the processor 132 may command the first switch module 134through the control end Ctrl2. In some embodiments, the processor 132may cause the first switch module 134 to turn on by transmitting a highsignal voltage. Thus, the one or more dummy loads 133-1, 133-2, . . . ,133-n may be electrically connected to the control system 120. In someembodiments, the processor 132 may cause the first switch module 134 toturn off by transmitting a low signal voltage. Thus, the one or moredummy loads 133-1, 133-2, . . . , 133-n may be electrically disconnectedfrom the diagnosis circuit system. The one or more coil arrays 290-1,290-2, . . . , 290-n and the one or more dummy loads 133-1, 133-2, . . ., 133-n may not be electrically connected to the control system 120 atthe same time. When the one or more coil arrays 290-1, 290-2, . . . ,290-n are electrically connected to the control system 120, theprocessor 132 may perform fault diagnosis on the tuning/detuning systembased on a comparison between an actual value and an expected value ofan electrical signal. For example, the processor 132 may determinewhether a short circuit and/or an open circuit exist in thetuning/detuning system based on a comparison between an actual value andan expected value of the first current. Upon a determination that ashort circuit and/or an open circuit exists in the tuning/detuningsystem, the processor 132 may cause the first switch module 134 to turnon. Then the one or more dummy loads 133-1, 133-2, . . . , 133-n may beelectrically connected to the diagnosis circuit. The processor 132 mayfurther determine an exact location in which the short/open circuitexists. For instance, the processor 132 may perform a comparison betweenan actual value and an expected value of the first current under one ormore various circumstances. Merely by way of example, the processor 132may determine that a short/open circuit exists in the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n or the oneor more coil arrays 290-1, 290-2, . . . , 290-n. As another example, theprocessor 132 may determine which one of the one or more tuning/detuningcircuit drivers 280-1, 280-2, . . . , 280-n and the one or more coilarrays 290-1, 290-2, . . . , 290-n the short/open circuit exists in.More details regarding the fault diagnosis may be found elsewhere in thepresent disclosure. See, e.g., FIGS. 6 to 14.

The second current sampling circuit 135 may be configured to sample asecond current. The second current may refer to a current outputted bythe one or more dummy loads 133-1, 133-2, . . . , 133-n and/or a currentbetween the common connecting end of the dummy loads and the ground. Thesecond current may be digitalized, for example, using ananalog-to-digital converter (ADC) of the second current sampling circuit135, which is illustrated below. The second current sampling circuit 135may be operatively connected to the processor 132 and electricallyconnected to the first switch module 134. When the first switch module134 turns on, the second current sampling circuit 135 may sample anactual value of the second current and output the actual value of thesecond current to the processor 132 through the output end Out3.

To facilitate the description of the tuning/detuning system and thefault diagnosis circuit system in the present disclosure, moredescriptions are illustrated below. As illustrated in FIG. 3, thepositive end of one end diode D2 may be electrically connected to theoutput end Out1 and the negative end of the other end diode D2 may beelectrically connected to the ground. In some embodiments, if theprocessor 132 selects the first voltage source 210 as the voltage sourceof the tuning/detuning circuit driver, i.e., the processor 132 causesthe tuning/detuning circuit driver to have the input end In1 as theinput end of the tuning/detuning circuit driver through the control endCtrl1, the output end Out1 may output a constant current to thecorresponding dummy loads. In these embodiments, the diodes D2 in thecorresponding dummy loads may conduct. Thus, a current passing throughthe corresponding dummy load may be the same or substantially the sameas the constant current. Accordingly, an expected value of the secondcurrent may be determined based on the number of dummy loads whosevoltage source is the first voltage source 210, as illustrated below:

I ₂ =I _(c) ×k,  (2)

where I₂ may refer to the expected value of the second current, I_(C)may refer to the constant current, and k may refer to the number ofdummy loads whose voltage source is the first voltage source 210.

For example, if the voltage source of the total dummy loads (i.e., theone or more dummy loads 133-1, 133-2, . . . , 133-n) is the firstvoltage source 210, k is n. Then, the expected value of the firstcurrent may be or approximately be I_(C)*n. As another example, if thevoltage source of the total dummy loads (i.e., all of the one or moredummy loads 133-1, 133-2, . . . , 133-n) is the second voltage source220, k is 0. Then, the expected value of the second current may be zeroor approximately zero. It should be noted that when the voltage sourceof an additional dummy load is changed to the first voltage source 210,the second current may increase by an increment. The increment may bethe same as or substantially the same as I_(c).

Accordingly, the processor 132 may be configured to perform faultdiagnosis on the one or more output ends Out1 of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n according tothe second current. In some embodiments, the processor 132 may performthe fault diagnosis based on a comparison between an actual value and anexpected value of the second current. FIG. 11 illustrates an exemplaryprocess for fault diagnosis.

FIG. 4 illustrates an exemplary control system 120 including a faultdiagnosis circuit system for a tuning/detuning system according to someembodiments of the present disclosure. The exemplary control system 120as illustrated in FIG. 4 may include the first voltage source 210, thesecond voltage source 220, the processor 132, the first current samplingcircuit 131, the one or more tuning/detuning circuit driver 280-1,280-2, . . . , 280-n, the one or more coil array 290-1, 290-2, . . . ,290-n, the one or more dummy loads 133-1, 133-2, . . . , 133-n, thesecond current sampling circuit 135, and the first switch module 134,similar to those illustrated in FIGS. 2 and 3, the descriptions of whichare not repeated here. It is understood that more details areillustrated in the coil array 290-1 than in the coils arrays 290-2, . .. , 290-n for illustration purposes. The coils arrays 290-2, . . . ,290-n may be the same as or different from the coil array 290-1, asdescribed with reference to FIGS. 2 and 3. Further, the exemplarycontrol system 120 as illustrated in FIG. 4 may include a current limitresistor R3, a second switch module 136, and a voltage comparisoncircuit 137.

The current limit resistor R3 may be electrically connected to thesecond switch module 136 in parallel. A first end of the current limitresistor R3 may be electrically connected to at least one of the inputend(s) In2 of the one or more tuning/detuning circuit drivers 280-1,280-2, . . . , 280-n. A second end of the current limit resistor R3 maybe electrically connected to the second voltage source 220. When thesecond switch module 136 turns off, the second voltage source 220 may beelectrically connected to the one or more tuning/detuning circuitdrivers 280-1, 280-2, . . . , 280-n through the current limit resistorR3.

The second switch module 136 may include a first end, a second end, anda control end. The first end may be electrically connected to the outputend Vcc2 of the second voltage source 220. The second end may beelectrically connected to at least one of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n. The controlend may be electrically connected to the processor 132. In someembodiments, the second switch module 136 may be a switch, a relay, orthe like, or the combination thereof.

Accordingly, the processor 132 may command the second switch module 136through the control end. For example, the processor 132 may cause thesecond switch module 136 to turn on by transmitting a high signalvoltage. As another example, the processor 132 may cause the secondswitch module 136 to turn off by transmitting a low signal voltage. Insome embodiments, when the control system 120 as illustrated in FIG. 4is idle, the processor 132 may cause the second switch module 136 toturn off, and the processor 132 may further perform fault diagnosis onthe one or more tuning/detuning circuit drivers. In some embodiments,when the control system 120 is performing a scan, the processor 132 maycause the second switch module 136 to turn on.

The voltage comparison circuit 137 may be configured to sample a firstvoltage and compare the first voltage and a reference voltage, asillustrated in equation (3). The first voltage may refer to a voltageoutputted by the first end of the current limit resistor R3. The voltagecomparison circuit 137 may include a voltage sampling end and an outputend. The voltage sampling end may be electrically connected to the firstend of the current limit resistor R3. The output end may be operativelyconnected to the processor 132. Accordingly, the processor 132 mayperform fault diagnosis on the one or more tuning/detuning circuitdrivers 280-1, 280-2, . . . , 280-n based on the first voltage. In someembodiments, the processor 132 may perform the fault diagnosis based ona comparison between an actual value and an expected value of the firstvoltage. FIGS. 12 and 13 illustrate exemplary processes for the faultdiagnosis.

In some embodiments, the control system 120 as illustrated in FIG. 4 mayfurther include a third switch module 138. The third switch module 138may include a first end, a second end, and a control end. The first endmay be electrically connected to the output end Vcc2 of the secondvoltage source 220. The second end may be electrically connected to thecurrent limit resistor R3. The control end may be operatively connectedto the processor 132. In some embodiments, the third switch module 138may be a switch, a relay, or the like, or the combination thereof.Accordingly, the processor 132 may command the third switch module 138through the control end. For example, the processor 132 may cause thethird switch module 138 to turn on by transmitting a high signalvoltage. As another example, the processor 132 may cause the thirdswitch module 138 to turn off by transmitting a low signal voltage. Insome embodiments, when determining that short circuit exists in thetuning/detuning system of the local coils, the processor 132 may causethe third switch module 138 to turn off, thus protecting thetuning/detuning system.

In some embodiments, the tuning/detuning system of the local coils mayfurther include one or more inductors L1 in addition to the firstvoltage source 210, the second voltage source 220, the one or more coilarrays 290-1, 290-2, . . . , 290-n and the one or more tuning/detuningcircuit drivers 280-1, 280-2, . . . , 280-n that are illustrated inFIGS. 2 and 3. An inductor L1 may correspond to a coil array (e.g.,290-1, 290-2, . . . , 290-n).

In some embodiments, a dummy load (e.g., 133-1, 133-2, . . . , 133-n)may include a second inductor L2. The second inductor L2 may beelectrically connected to the second diode D2 in series. A dummy load(e.g., 133-1, 133-2, . . . , 133-n) may be electrically connected to atuning/detuning circuit driver (e.g., 280-1, 280-2, . . . , 280-n)through an electrical node (e.g., N1, N2, Nn illustrated in FIG. 4). Anelectrical node may be electrically connected to another electrical nodewith the same mark. For example, the electrical node N1 on the dummyload 133-1 branch may be electrically connected to the electrical nodeN1 on the tuning/detuning circuit driver branch.

As illustrated in FIG. 4, the first current sampling circuit 131 mayinclude a first sampling resistor R1, a first operational amplifieropamp1, and a first analog-to-digital converter ADC1. The first samplingresistor R1 may be electrically connected to the first voltage source210 and at least one of the one or more tuning/detuning circuit drivers280-1, 280-2, . . . , 280-n. As illustrated, the first end of the firstsampling resistor R1 may be electrically connected to the output endVcc1 of the first voltage source 210. The second end of the firstsampling resistor R1 may be electrically connected to at least one ofthe first input end(s) In1 of the one or more tuning/detuning circuitdrivers 280-1, 280-2, . . . , 280-n. At the same time, the first end ofthe first sampling resistor R1 may be electrically connected to thepositive end of the first operational amplifier opamp1, and the secondend of the first sampling resistor R1 may be electrically connected tothe negative end of the first operational amplifier opamp1. The ADC1 maybe operatively connected to the processor 132 and the first operationalamplifier opamp1. As illustrated, the output end of the firstoperational amplifier opamp1 may be electrically connected to the inputend of the ADC1, and the output end of the ADC1 may be operativelyconnected to the processor 132. The ADC1 may be configured to digitalizethe first current. In some embodiments, the first sampling resistor R1may be a power resistor, for example, a high precision power resistor.

The second current sampling circuit 135 may include a second samplingresistor R2, a second operational amplifier opamp2, and a secondanalog-to-digital converter ADC2. The second sampling resistor R2 may beelectrically connected to the first switch module 134 in series. Thefirst end of the second sampling resistor R2 may be electricallyconnected to the positive end of the second operational amplifieropamp2, and the second end of the second sampling resistor R2 may beelectrically connected to the negative end of the second operationalamplifier opamp2. The ADC2 may be operatively connected to the processor132 and the second operational amplifier opamp2. As illustrated, theoutput end of the second operational amplifier opamp2 may beelectrically connected to the input end of the ADC2, and the output endof the ADC2 may be operatively connected to the processor 132. The ADC2may be configured to digitalize the second current.

The voltage comparison circuit 137 may include a fourth resistor R4, afifth resistor R5, and a comparator Cmp. The first end of the fourthresistor R4 may be electrically connected to the voltage sampling end ofthe voltage comparison circuit 137, i.e., the first end of the currentlimit resistor R3. The second end of the fourth resistor R4 may beelectrically connected to the first input end of the comparator Cmp. Thefirst end of the fifth resistor R5 may be electrically connected to thefirst input end of the comparator Cmp. The second end of the fifthresistor R5 may be electrically connected to the ground. The secondinput end of the comparator Cmp may be electrically connected to areference voltage Vref. The output end of the comparator Cmp may beoperatively connected to the processor 132. The comparator Cmp may beconfigured to compare the first voltage and a reference voltage, whichis illustrated below. See, e.g., equation (3) and the descriptionthereof.

It should be noted that the exemplary constructions are merely providedfor the purposes of illustration, and not intended to limit the scope ofthe present disclosure. The first current sampling circuit 131, thesecond current sampling circuit 135 and/or the voltage comparisoncircuit 137 may include other constructions.

Merely by way of example, when the control system 120 as illustrated inFIG. 4 is idle, the processor 132 may command the second switch module136 to turn off. The comparator Cmp may compare the reference voltageVref and the first voltage, and output a signal indicating a comparisonresult. Then, the processor 132 may perform the fault diagnosis on thetuning/detuning system based on the comparison result. The referencevoltage Vref may fall within a range from V₂×R₅/(R₄+R₅) to zero, asillustrated below:

V _(ref)∈(V ₂ ×R ₅/(R ₄ +R ₅),0),  (3)

where V₂ may refer to the constant negative voltage outputted by thesecond voltage source 220.

Since the second voltage source 220 outputs a constant negative voltage,when a short circuit does not exist in a tuning/detuning circuit driverwhose voltage source is the second voltage source 220 and/or when ashort circuit does not exist in the corresponding coil array, the firstvoltage sampled by the voltage comparison circuit 137 may beapproximately the same as the constant negative voltage, i.e., V₁≈V₂.The comparator Cmp may output a signal indicating that the referencevoltage is greater than the first voltage. On the other hand, when ashort circuit exists in a tuning/detuning circuit driver whose voltagesource is the second voltage source 220 and/or when a short circuitexists in the corresponding coil array, the voltage of the current limitresistor R3 may be approximately the same as the constant negativevoltage. Thus, the first voltage sampled by the voltage comparisoncircuit 137 may increase to approximately zero, i.e., V₁≈0. Thecomparator Cmp may output a signal indicating that the reference voltageis less than the first voltage. Therefore, the processor 132 maydetermine whether a short circuit exists in a tuning/detuning circuitdriver and the corresponding coil array based on the signal outputted bythe comparator Cmp.

FIG. 5 illustrates an exemplary first voltage source 210 according tosome embodiments of the present disclosure. As illustrated, the firstvoltage source 210 may include a DC-DC controller 211, a sixth resistorR6, and a variable resistor 212.

The DC-DC controller 211 may include an output end Out5 and a feedbackinput. The feedback input may include a VSENSE pin or other pins. Thevariable resistor 212 may include a first end, a second end, and acontrol end. The sixth resistor R6 may include a first end and a secondend. The output end Out5 of the DC-DC controller 211 and the first endof the variable resistor 212 may be electrically connected to the outputend Vcc1 of the first voltage source 210. The VSENSE pin of the DC-DCcontroller 211 and the second end of the variable resistor 212 may beelectrically connected to the first end of the sixth resistor R6. Thesecond end of the sixth resistor R6 may be electrically connected to theground. The control end of the variable resistor 212 may be operativelyconnected to the processor 132.

Accordingly, the processor 132 may be configured to adjust theequivalent resistance value of the variable resistor 212 through thecontrol end. In some embodiments, the processor 132 may adjust theequivalent resistance value of the variable resistor 212 according tothe configuration(s) of coil array(s) in the detuning status. Further,the processor 132 may adjust the voltage outputted by the output endVcc1 of the first voltage source 210.

The DC-DC controller 211 may be configured to convert a direct currentvoltage V+ to a needed direct current voltage and output the neededdirect current voltage. The VSENSE pin may be configured to output aconstant voltage. The voltage outputted by the first voltage source 210may be illustrated below:

V ₃=(R _(eq) +R ₆)V _(h) /R ₆,  (4)

where V₃ may refer to the voltage outputted by the first voltage source210, R_(eq) may refer to the equivalent resistance value of the variableresistor 212, the V_(h) may refer to the constant voltage outputted bythe VSENSE pin.

In some embodiments, the DC-DC controller 211 may further include anenable end EN. The enable end EN may be operatively connected to theprocessor 132 to retrieve signals from the processor 132. The signalsmay include an enable signal and a disable signal. The enable signal maycause the first voltage source 210 to output a positive voltage. Thedisable signal may cause the first voltage source 210 to stop outputtingthe positive voltage. For example, when determining that a fault (e.g.,a short circuit, an open circuit) exists, the processor 132 may transmitthe disable signal to the DC-DC controller 211 through the enable endEN. The disable signal may cause the DC-DC controller 211 to stopworking. Thus, the first voltage source 210 may stop outputting thepositive voltage. Merely by way of example, the model of the DC-DCcontroller 211 may be TPS54620.

The variable resistor 212 may include a plurality of resistors and aplurality of fourth switch modules. The processor 132 may cause a firstfourth module to turn on/off by transmitting a high/low signal voltageto the control end of the fourth switch module. Thus, the processor 132may adjust the equivalent resistance value of the variable resistor 212,and then adjust the output voltage of the first voltage source 210accordingly. See, e.g., equation (4).

For the purposes of illustration, the variable resistor 212 may includea seventh resistor R7, an eighth resistor R8, a ninth resistor R9, atenth resistor R10, a fourth switch module 213, a fourth switch module214, a fourth switch module 215, and a fourth switch module 216. Theseventh resistor R7 may be electrically connected to the fourth switchmodule 213. The fourth switch module 213 may be electrically connectedto the eighth resistor R8 in series. The eighth resistor R8 may beelectrically connected to the ninth resistor R9. The ninth resistor R9may be electrically connected to the tenth resistor R10. The fourthswitch module 214 may be electrically connected to a branch includingthe fourth switch module 213 and the eighth resistor R8. The fourthswitch module 215 may be electrically connected to a branch includingthe fourth switch module 213, the eighth resistor R8, and the ninthresistor R9. The fourth switch module 216 may be electrically connectedto a branch including the fourth switch module 213, the eighth resistorR8, the ninth resistor R9, and the tenth resistor R10. Then, theprocessor 132 may adjust the equivalent resistance value of the variableresistor 212 by controlling the fourth switch module 213, the fourthswitch module 214, the fourth switch module 215, and the fourth switchmodule 215.

In some embodiments, the first voltage source 210 may further include athird inductor L3 and a first capacitor C1. One end of the thirdinductor L3 may be electrically connected to the output end Out5 of theDC-DC controller 211. The other end of the third inductor L3 may beelectrically connected to one end of the first capacitor C1, one end ofthe variable resistor 212, and the output end Vcc1 of the first voltagesource 210. The other end of the first capacitor C1 may be electricallyconnected to the ground. The combination of the third inductor L3 andthe first capacitor C1, forming a passive filter, may be configured tofilter out single tuning or double tuning harmonics from the voltage.

In order to decrease the power loss of the one or more tuning/detuningcircuit drivers 280-1, 280-2, . . . , 280-n, it is desired to decreasethe voltage of the one or more tuning/detuning circuit drivers 280-1,280-2, . . . , 280-n. As illustrated in FIGS. 2 to 4, the voltage of theone or more tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-nmay be the difference between the output voltage of the first voltagesource 210 and the voltage of the one or more coil arrays 290-1, 290-2,. . . , 290-n. Thus, it is desired to decrease the output voltage of thefirst voltage source 210. Then the processor 132 may determine theminimum value of the output voltage of the first voltage source 210. Theminimum value of the output voltage of the first voltage source 210 maybe determined based on the configuration(s) of the coil array(s).According to the configuration of a coil array, the processor 132 maydetermine the number of first diodes D1 in each branch of the coil arraythat is in the detuning status. Further, the processor 132 may determinethe number of first diodes D1 in a branch that includes the most firstdiodes D1. Thus, the processor 132 may determine the minimum outputvoltage of the first voltage source 210. Merely by way of example, theminimum output voltage of the first voltage source 210 may beillustrated below:

V _(3min) =V _(s) +M×V _(d),  (5)

where V_(3min) may refer to the minimum output voltage of the firstvoltage source 210, V_(s) may refer to the minimum voltage of the one ormore tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n, V_(d)may refer to the voltage of a first diode that is conducting, and M mayrefer to the number of first diodes in a branch that includes the mostfirst diodes.

FIG. 6 illustrates an exemplary process for fault diagnosis of atuning/detuning system according to some embodiments of the presentdisclosure. Process 600 may be performed on the control system 120 asillustrated in FIGS. 2 to 4.

In 601, the processor 132 may determine an expected value of anelectrical signal of a sampling circuit according to at least one of theoperation status of the RF system 112, the tuning or detuning status oflocal coils, and the types of voltage sources set by the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n.

The operation status of the RF system 112 may include an idle status anda scanning status. When the RF system 112 is idle, the local coils maybe electrically connected to the RF system 112 or not. When the RFsystem 112 is performing a scanning, the local coils may be electricallyconnected to the RF system 112. When the local coils are electricallyconnected to the RF system 112, the one or more coil arrays 290-1,290-2, . . . , 290-n of the local coils may be electrically connected tothe output ends Out1 of the one or more tuning/detuning circuit drivers280-1, 280-2, . . . , 280-n. When the local coils are electricallydisconnected from to the RF system 112, the one or more coil arrays290-1, 290-2, . . . , 290-n of the local coils may be electricallydisconnected from the output ends Out1 of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n.

The types of voltage sources set by the one or more tuning/detuningcircuit drivers 280-1, 280-2, . . . , 280-n may include the firstvoltage source 210 and the second voltage source 220.

The sampling circuit may include the first current sampling circuit 131,the second current sampling circuit 135, and the voltage comparisoncircuit 137. The electrical signal may include the first current sampledby the first current sampling circuit 131, the second current sampled bythe second current sampling circuit 135, and the first voltage sampledby the voltage comparison circuit 137.

In some embodiments, the expected value of the first current may bedetermined based on the number of coil arrays whose voltage source isthe first voltage source 210. For instance, the processor 132 maydetermine the expected value of the first current according to equation(1) described in connection with FIG. 2.

In some embodiments, the expected value of the second current may bedetermined based on the number of coil arrays whose voltage source isthe first voltage source 210. For instance, the processor 132 maydetermine the expected value of the second current according to equation(2) described in connection with FIG. 3.

In some embodiments, the expected value of the first voltage may beapproximately the same as the constant negative voltage outputted by thesecond voltage source 220. The processor 132 may determine the expectedvalue of the first voltage according to the descriptions of FIG. 4.

In 602, the processor 132 may obtain an actual value of the electricalsignal. In some embodiments, the processor 132 may obtain an actualvalue of the first current from the first current sampling circuit 131.In some embodiments, the processor 132 may obtain an actual value of thesecond current from the second current sampling circuit 135. In someembodiments, the processor 132 may obtain an actual value of the firstvoltage from the voltage comparison circuit 137.

In 603, the processor 132 may perform fault diagnosis on atuning/detuning system of the local coils based on the expected value ofthe electrical signal and the actual value of the electrical signal. Insome embodiments, the processor 132 may compare the expected value ofthe electrical signal and the actual value of the electrical signal.Further, the processor 132 may determine whether a fault exists in thetuning/detuning system according to the comparison. For example, uponthe determination that the actual value is approximately the same as theexpected value or that the difference between the actual value and theexpected value is below a threshold, the processor 132 may determinethat the tuning/detuning system is normal. As another example, upon thedetermination that the difference between the actual value and theexpected value exceeds a threshold, the processor 132 may determine thata fault exists in the tuning/detuning system. The fault may include ashort circuit and/or an open circuit.

It should be noted that the above description of process 600 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 7 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the first current according to someembodiments of the present disclosure. Process 700 may be an example ofthe process 600. Process 700 may be performed on the control system 120as illustrated in FIGS. 2 to 4.

In 701, upon the detection that the RF system 112 is idle and the localcoils are electrically connected to the RF system 112, the processor 132may cause the second voltage source 220 to serve as the voltage sourceof the one or more tuning/detuning circuit drivers 280-1, 280-2, . . . ,280-n. The processor 132 may determine a first expected range of thefirst current.

When the voltage source of the one or more tuning/detuning circuitdrivers 280-1, 280-2, . . . , 280-n is the second voltage source 220,the number of the coil arrays whose voltage source is the first voltagesource 210 is zero, i.e., m in equation (1) is zero. According toequation (1) illustrated in connection with FIG. 2, the expected valueof the first current may be zero. Thus, the processor 132 may determinethe first expected range of the first current as a range approachingzero. For example, the processor 132 may determine the first expectedrange of the first current as (−I_(e1), I_(e1)). I_(e1) may refer to asmall positive number, for example, 0.1, 0.2.

It should be noted that for the control system 120 illustrated in FIGS.3 and 4, when the local coils are electrically connected to the RFsystem 112, the one or more dummy loads 133-1, 133-2, . . . , 133-n areelectrically disconnected from the RF system 112. Accordingly, theprocessor 132 may cause the first switch module 134 to turn off.

In 702, the processor 132 may obtain an actual value of the firstcurrent. As illustrated in FIGS. 2 to 4, the actual value of the firstcurrent may be sampled by the first current sampling circuit 131.

In 703, the processor 132 may determine whether the actual value of thefirst current falls within the first expected range of the firstcurrent. In some embodiments, the processor 132 may determine whetherthe actual value of the first current falls within (−I_(e1), I_(e1)).

Upon the determination that the actual value of the first current fallswithin the first expected range of the first current, process 700 mayproceed to 704. In 704, the processor 132 may determine that no shortcircuit exists at the first input end(s) of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n.

Upon the determination that the actual value of the first current fallsoutside of the first expected range of the first current, process 700may proceed to 705. In 705, the processor 132 may determine that a shortcircuit exists at the first input end(s) of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n.

After executing operations 704 and 705, the processor 132 may continueto perform operation X, which is illustrated in FIG. 8.

It should be noted that the above description of process 700 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 8 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on a change of the first current accordingto some embodiments of the present disclosure. Process 800 may beperformed on the control system 120 as illustrated in FIGS. 2 to 4.

In 801, the processor 132 may cause the type of the voltage source ofone of the one or more tuning/detuning circuit drivers 280-1, 280-2, . .. , 280-n to change. For instance, if the voltage source of atuning/detuning circuit driver (e.g., 280-1, 280-2, . . . , 280-n) isoriginally the first voltage source 210, the processor 132 may cause itto change to the second voltage source 220. As another example, if thevoltage source of a tuning/detuning circuit driver (e.g., 280-1, 280-2,. . . , 280-n) is originally the second voltage source 220, theprocessor 132 may cause it to change to the first voltage source 210.

In 802, the processor 132 may obtain an actual value of the firstcurrent.

In 803, the processor 132 may determine whether the actual value of thefirst current increases/decreases by a predetermined increment inresponse to the change of the type of the voltage source of thetuning/detuning circuit driver.

Upon the determination that the actual value of the first currentincreases/decreases by a predetermined increment in response to thechange of the type of the voltage source of the tuning/detuning circuitdriver, process 800 may proceed to 804. In 804, the processor 132 maydetermine that the tuning/detuning circuit driver (e.g., 280-1, 280-2, .. . , 280-n) and/or the corresponding coil array are normal.

Upon the determination that the actual value of the first current failsto increase/decrease by a predetermined increment, process 800 mayproceed to 805. In 805, the processor 132 may determine that a faultexists in the tuning/detuning circuit driver (e.g., 280-1, 280-2, . . ., 280-n) and/or the corresponding coil array.

Under different circumstances, process 800 may include differentspecific operations. Some examples of such specific operations ofprocess 800 may be found below. It should be noted that the descriptionbelow is merely for the purposes of illustration, and is not intended tobe limiting.

In some embodiments, when the RF system 112 is idle and the local coilsare electrically connected to the RF system 112, and the voltage sourceof the one or more tuning/detuning circuit drivers 280-1, 280-2, . . . ,280-n is the second voltage source 220 (i.e., the embodimentsillustrated in FIG. 7), in 801, the processor 132 may cause the voltagesource of a tuning/detuning circuit driver to change to the firstvoltage source 210. The tuning/detuning circuit driver whose voltagesource is changed may be any one of the one or more tuning/detuningcircuit drivers 280-1, 280-2, . . . , 280-n.

It should be understood that process 800 may be repeated many times, forexample, for all the one or more tuning/detuning circuit drivers 280-1,280-2, . . . , 280-n. In each repetition, the voltage source of onetuning/detuning circuit driver may be changed to the first voltagesource 210 or the second voltage source 220. In some embodiments, theprocessor 132 may change the type of the voltage source of the one ormore tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n one byone in an order. For example, the processor 132 may change the type ofthe voltage source of the one or more tuning/detuning circuits from thetuning/detuning circuit driver 280-1, the tuning/detuning circuit driver280-2, to the tuning/detuning circuit driver 280-n. As another example,the processor 132 may change the type of the voltage source of the oneor more tuning/detuning circuits from the tuning/detuning circuit driver280-n, the tuning/detuning circuit driver 280-(n−1), to thetuning/detuning circuit driver 280-1.

When the voltage source of the tuning/detuning circuit driver is changedto the first voltage source 210, the number of coil arrays whose voltagesource is the first voltage source 210 may increase by one. In someembodiments, before executing process 800 for a next tuning/detuningcircuit driver, the processor 132 may cause the type of the voltagesource of the tuning/detuning circuit driver that has been changed inthe previous iteration of process 800 to change back from the firstvoltage source 210 to the second voltage source 220. Thus, each timeprocess 800 is performed, the number of coil arrays whose voltage sourceis the first voltage source 210 may always be changed to one from zero.Accordingly, except for the tuning/detuning circuit driver whose voltagesource is changed, the voltage source of the other tuning/detuningcircuit drivers may remain to be the second voltage source 220. In someembodiments, before executing process 800 for a next tuning/detuningcircuit driver, the processor 132 does not cause the type of the voltagesource of the tuning/detuning circuit driver that has been changed inthe previous iteration of process 800 to change back from the firstvoltage source 210 to the second voltage source 220. Accordingly, exceptfor the tuning/detuning circuit driver whose voltage source is changed,the voltage source of the other tuning/detuning circuit drivers thathave been changed in the previous iterations of process 800 may beallowed to remain changed (i.e., the voltage source of each of the othertuning/detuning circuit drivers remains the first voltage source 210).Thus, each time process 800 is performed, the number of coil arrayswhose voltage source is the first voltage source 210 may increase byone, for example, from zero to one, from one to two, . . . , from (n−1)to n. Accordingly, the expected value of the first current may alwaysincrease by Ic based on equation (1).

It should be noted that, in the present disclosure, the changing of thetype of the voltage source of a tuning/detuning circuit driver may beperformed in two ways as illustrated above. For brevity, in thefollowing description, the two ways of the changing of the type of thevoltage source are not illustrated separately.

Then, in 803, the processor 132 may determine whether the actual valueof the first current increases by a predetermined increment. Thepredetermined increment may be set according to the change of theexpected value of the first current, e.g., Ic. For instance, thepredetermined increment may be a value closer to Ic. Merely by way ofexample, the predetermined increment may fall within a range centered atIc, illustrated below:

D∈(I _(c) −ΔI,I _(c) +ΔI),  (6)

where D may refer to the predetermined increment, Ic may refer to theconstant current outputted by the first voltage source 210, and Δ/I mayrefer to a deviation of the current for a coil array. Such a deviationmay be caused by, e.g., a tolerable fluctuation of the voltage source, atolerable imperfection of the tuning/detuning circuit driver or the coilarray, or the like, or a combination thereof.

In 804, upon the determination that the actual value of the firstcurrent increases by the predetermined increment (i.e., D), theprocessor 132 may determine that the tuning/detuning circuit driver andthe corresponding coil array are normal. In 805, upon the determinationthat the actual value of the first current fails to increase by thepredetermined increment (i.e., D), the processor 132 may determine thatan open circuit exists in the tuning/detuning circuit driver and/or thecorresponding coil array.

In some embodiments, when the RF system 112 is performing a scan and thelocal coils are electrically connected to the RF system 112 (i.e., theembodiments illustrated in FIG. 9), in 801, the processor 132 may changethe voltage source of a tuning/detuning circuit driver whose voltagesource is the second voltage source 220 to the first voltage source 210.When the voltage source of the tuning/detuning circuit driver is changedto the first voltage source 210, the number of coil arrays whose voltagesource is the first voltage source 210 may increase by one. Accordingly,the expected value of the first current may increase by Ic based onequation (1). The predetermined increment may be the same as Dillustrated in equation (6). Then, in 803, the processor 132 maydetermine whether the actual value of the first current increases by thepredetermined increment (i.e., D). In 804, upon the determination thatthe actual value of the first current increases by the predeterminedincrement (i.e., D), the processor 132 may determine that thetuning/detuning circuit driver and the corresponding coil array arenormal. In 805, upon the determination that the actual value of thefirst current fails to increase by the predetermined increment (i.e.,D), the processor 132 may determine that an open circuit exists in thetuning/detuning circuit driver and/or the corresponding coil array.

Alternatively, in 801, the processor 132 may cause the voltage source ofa tuning/detuning circuit whose voltage source is the first voltagesource 210 to change to the second voltage source 220. When the voltagesource of the tuning/detuning circuit driver is changed to the secondvoltage source 220, the number of coil arrays whose voltage source isthe first voltage source 210 may decrease by one. Accordingly, theexpected value of the first current may decrease by Ic based on equation(1). The predetermined increment may be the same as D illustrated inequation (6). Then, in 803, the processor 132 may determine whether theactual value of the first current decreases by the predeterminedincrement (i.e., D). In 804, upon the determination that the actualvalue of the first current decreases by the predetermined increment(i.e., D), the processor 132 may determine that the tuning/detuningcircuit driver and the corresponding coil array are normal. In 805, uponthe determination that the actual value of the first current fails todecrease by the predetermined increment (i.e., D), the processor 132 maydetermine that an open circuit exists in the tuning/detuning circuitdriver and/or the corresponding coil array.

In some embodiments, when the RF system 112 is idle and the local coilsare electrically disconnected from the RF system 112, and the voltagesource of the one or more tuning/detuning circuit drivers 280-1, 280-2,..., 280-n is the second voltage source 220 (i.e., the embodimentsillustrated in FIG. 10), in 801, the processor 132 may cause the type ofthe voltage source of one of the one or more tuning/detuning circuitdrivers 280-1, 280-2, . . . , 280-n to change to the first voltagesource 210. The number of dummy loads whose voltage source is the firstvoltage source 210 may increase by one. Accordingly, the expected valueof the first current may increase by Ic. The predetermined increment maybe the same as D illustrated in equation (6). Then, in 803, theprocessor 132 may determine whether the actual value of the firstcurrent increases by the predetermined increment (i.e., D). In 804, uponthe determination that the actual value of the first current increasesby the predetermined increment (i.e., D), the processor 132 maydetermine that no short circuit exists at the first input end of thetuning/detuning circuit driver. In 805, upon the determination that theactual value of the first current fails to increase by the predeterminedincrement (i.e., D), the processor 132 may determine that a shortcircuit exists at the first input end of the tuning/detuning circuitdriver.

It should be noted that the above description of process 800 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 9 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the first current according to someembodiments of the present disclosure. Process 900 may be an example ofthe process 600. Process 900 may be performed on the control system 120as illustrated in FIGS. 2 to 4.

In 901, upon the detection that the RF system 112 is performing a scanand the local coils are electrically connected to the RF system 112, theprocessor 132 may determine a second expected range of the first currentaccording to the number of coil arrays whose voltage source is the firstvoltage source 210. When the RF system 112 is performing a scan, thestatus (e.g., a tuning status, a detuning status) of the one or morecoil arrays 290-1, 290-2, . . . , 290-n may be determined according tothe needs of the scan. Thus, the types of the voltage sources of the onemore coil arrays 290-1, 290-2, . . . , 290-n may be determined accordingto the needs of the scan. Accordingly, the number of coil arrays whosevoltage source is the first voltage source 210 may be determinedaccording to the needs of the scan. According to equation (1)illustrated in connection with FIG. 2, the processor 132 may determinethe expected value of the first current based on the number of coilarrays whose voltage source is the first voltage source 210. Then, theprocessor 132 may determine the second expected range of the firstcurrent according to the expected value of the first current.

Merely by way of example, the second expected range may be a rangecentered at the expected value of the first current, illustrated below:

(I ₁ −ΔI×m,I ₁ +ΔI×m),  (7)

where may refer to the expected value of the first current and bedetermined as (I_(c)×m) according to equation (1), m may refer to thenumber of coil arrays whose voltage source is the first voltage source210, and ΔI may refer to a deviation of the current for a coil array.

In 902, the processor 132 may obtain an actual value of the firstcurrent. As illustrated in FIGS. 2 to 4, the actual value of the firstcurrent may be sampled by the first current sampling circuit 131.

In 903, the processor 132 may determine whether the actual value of thefirst current falls within the second expected range of the firstcurrent. In some embodiments, the processor 132 may determine whetherthe actual value of the first current falls within (I₁−ΔI×m,I₁+ΔI×m).Upon the determination that the actual value of the first current fallswithin the second expected range of the first current, process 900 mayproceed to 904. In 904, the processor 132 may determine that the one ormore tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n and theone or more corresponding coil arrays 290-1, 290-2, . . . , 290-n arenormal.

Upon the determination that the actual value of the first current islower than the lower limit of the second expected range of the firstcurrent, process 900 may proceed to 905. In 905, the processor 132 maydetermine that an open circuit exists in at least one of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n and/or theone or more corresponding coil arrays 290-1, 290-2, . . . , 290-n.

Upon the determination that the actual value of the first current isgreater than the upper limit of the second expected range of the firstcurrent, process 900 may proceed to 906. In 906, the processor 132 maydetermine that a short circuit exists in at least one of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n and/or theone or more corresponding coil arrays 290-1, 290-2, . . . , 290-n.

After executing operations 905 and 906, the processor 132 cause the RFsystem 112 to stop scanning. Then the processor 132 may continue toperform operation X, which is illustrated in FIG. 8.

It should be noted that the above description of process 900 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 10 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the first current according to someembodiments of the present disclosure. Process 1000 may be an example ofthe process 600. Specifically, process 1000 may be an exemplary processfor the fault diagnosis of the one or more dummy loads 133-1, 133-2, . .. , 133-n. Process 1000 may be performed on the control system 120 asillustrated in FIGS. 3 and 4.

In 1001, upon the detection that the RF system 112 is idle and the localcoils are electrically disconnected from the RF system 112, theprocessor 132 may cause the second voltage source 220 to serve as thevoltage source of the one or more tuning/detuning circuit drivers 280-1,280-2, . . . , 280-n. The processor 132 may determine a third expectedrange of the first current.

Since the local coils are electrically disconnected from the RF system112, the processor 132 may cause the first switch module 134 to turn on.Thus, the one or more dummy loads 133-1, 133-2, . . . , 133-n may beelectrically connected to the RF system 112. In this case, the voltagesource of the one or more dummy loads 133-1, 133-2, . . . , 133-n may bethe second voltage source 220, and the number of dummy loads whosevoltage source is the first voltage source 210 is zero. The expectedvalue of the first current may be zero. Thus, the processor 132 maydetermine the third expected range of the first current as a rangeapproaching zero. In some embodiments, the processor 132 may determinethe third expected range of the first current as the same as the firstexpected range of the first current, for example, (−I_(e1), I_(e1)).I_(e1) may refer to a small positive number, for example, 0.1, 0.2.

In 1002, the processor 132 may obtain an actual value of the firstcurrent. As illustrated in FIGS. 2 and 3, the actual value of the firstcurrent may be sampled by the first current sampling circuit 131.

In 1003, the processor 132 may determine whether the actual value of thefirst current falls within the third expected range of the firstcurrent. In some embodiments, the processor 132 may determine whetherthe actual value of the first current falls within (−I_(e1), I_(e1)).

Upon the determination that the actual value of the first current fallswithin the third expected range of the first current, process 1000 mayproceed to 1004. In 1004, the processor 132 may determine that no shortcircuit exists at the first input end(s) of the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n. Afterexecuting operation 1004, the processor 132 may continue to performoperation Z, which is illustrated in FIG. 11.

Upon the determination that the actual value of the first current fallsoutside of the third expected range of the first current, process 1000may proceed to 1005. In 1005, the processor 132 may determine that ashort circuit exists at at least one of the first input end(s) of theone or more tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n.After executing operation 1005, the processor 132 may continue toperform operation X, which is illustrated in FIG. 8.

It should be noted that the above description of process 1000 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 11 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on a change of the first current and thesecond current according to some embodiments of the present disclosure.Process 1100 may be performed on the control system 120 as illustratedin FIGS. 3 and 4.

In 1101, the processor 132 may cause the type of the voltage source ofone of the one or more tuning/detuning circuit drivers 280-1, 280-2, . .. , 280-n to change to the first voltage source 210. Accordingly, thenumber of dummy loads whose voltage source is the first voltage source210 may increase by one. Accordingly, the expected value of the firstcurrent may increase by Ic according to equation (1).

In 1102, the processor 132 may obtain an actual value of the firstcurrent after the changing. The actual value of the first current may besampled by the first current sampling circuit 131.

In 1103, the processor 132 may determine whether the actual value of thefirst current after the changing increases by a predetermined increment.The predetermined increment for the first current may be determinedaccording to equation (6). In some embodiments, the processor 132 maydetermine whether the actual value of the first current increases by D.

Upon the determination that the actual value of the first current failsto increase by the predetermined increment (e.g., D), process 1100 mayproceed to 1108. In 1108, the processor 132 may determine that an opencircuit exists in the tuning/detuning circuit driver (e.g., 280-1,280-2, . . . , 280-n).

Upon the determination that the actual value of the first currentincreases by the predetermined increment (e.g., D), process 1100 mayproceed to 1104. In 1104, the processor 132 may obtain an actual valueof the second current. The actual value of the second current may besampled by the second current sampling circuit 135.

In 1105, the processor 132 may determine whether the actual value of thesecond current increases by a predetermined increment. Since the numberof dummy loads whose voltage source is the first voltage source 210increases by one, the actual value of the second current may increase byaccording to equation (2). Thus, in some embodiments, the predeterminedincrement of the second current may be the same as D illustrated inequation (6).

Upon the determination that the actual value of the second currentincreases by the predetermined increment (e.g., D), process 1100 mayproceed to 1106. In 1106, the processor 132 may determine that no shortcircuit exists at the output end of the tuning/detuning circuit driver(e.g., 280-1, 280-2, . . . , 280-n).

Upon the determination that the actual value of the second current failsto increase by the predetermined increment (e.g., D), process 1100 mayproceed to 1107. In 1107, the processor 132 may determine that a shortcircuit exists at the output end of the tuning/detuning circuit driver(e.g., 280-1, 280-2, . . . , 280-n).

It should be noted that the above description of process 1100 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 12 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the first voltage according to someembodiments of the present disclosure. Process 1200 may be an example ofthe process 600. Process 1200 may be performed on the control system 120as illustrated in FIG. 4.

In 1201, upon the detection that the RF system 112 is idle and the localcoils are electrically connected to the RF system 112, the processor 132may cause the second voltage source 220 to serve as the voltage sourceof the one or more tuning/detuning circuit drivers 280-1, 280-2, . . . ,280-n. In some embodiments, the processor 132 may cause the secondswitch module 136 to turn off, thus, the current limit resistor R3 maybe electrically connected to the RF system 112. The processor 132 maydetermine a first expected value of the first voltage. As illustrated inFIG. 4, the first expected value of the first voltage may beapproximately the same as the constant negative voltage outputted by thesecond voltage source 220 (i.e., V₂).

In 1202, the processor 132 may obtain an actual value of the firstvoltage. The first voltage may be sampled by the voltage comparisoncircuit 137.

In 1203, the processor 132 may determine whether the actual value isgreater than the first expected value. In some embodiments, theprocessor 132 may determine whether the actual value of the firstvoltage is greater than V₂.

Upon the determination that the actual value is greater than the firstexpected value (e.g., V₂), process 1200 may proceed to 1204. In 1204,the processor 132 may determine that no short circuit exists in the oneor more tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-nand/or one or more corresponding coil arrays 290-1, 290-2, . . . ,290-n.

Upon the determination that the actual value is not greater than thefirst expected value (e.g., V₂), process 1200 may proceed to 1205. In1205, the processor 132 may determine that a short circuit exists in atleast one of the one or more tuning/detuning circuit drivers 280-1,280-2, . . . , 280-n and one or more corresponding coil arrays 290-1,290-2, . . . , 290-n.

It should be noted that the above description of process 1200 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 13 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the first voltage according to someembodiments of the present disclosure. Process 1300 may be an example ofthe process 600. Process 1300 may be performed on the control system 120as illustrated in FIG. 4.

In 1301, upon the detection that the RF system 112 is idle and the localcoils are electrically disconnected from the RF system 112, theprocessor 132 may cause the second voltage source 220 to serve as thevoltage source of the one or more tuning/detuning circuit drivers 280-1,280-2, . . . , 280-n. In some embodiments, the processor 132 may causethe second switch module 136 to turn off so that the current limitresistor R3 may be electrically connected to the RF system 112. Theprocessor 132 may determine a second expected value of the firstvoltage. The second expected value of the first voltage may be the sameas the first expected value of the first voltage. As illustrated in FIG.4, the second expected value of the first voltage may be approximatelythe same as the constant negative voltage outputted by the secondvoltage source 220 (i.e., V₂).

In 1302, the processor 132 may obtain an actual value of the firstvoltage. The first voltage may be sampled by the voltage comparisoncircuit 137.

In 1303, the processor 132 may determine whether the actual value isgreater than the second expected value. In some embodiments, theprocessor 132 may determine whether the actual value of the firstvoltage is greater than V₂.

Upon the determination that the actual value is greater than the secondexpected value (e.g., V₂), process 1300 may proceed to 1304. In 1304,the processor 132 may determine that no short circuit exists in the oneor more tuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n.

Upon the determination that the actual value is not greater than thesecond expected value (e.g., V₂), process 1300 may proceed to 1305. In1305, the processor 132 may determine that a short circuit exists in atleast one of the one or more tuning/detuning circuit drivers 280-1,280-2, . . . , 280-n.

It should be noted that the above description of process 1300 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

FIG. 14 illustrates an exemplary process for fault diagnosis of atuning/detuning system based on the electrical signal according to someembodiments of the present disclosure. Process 1400 may be an example ofthe process 600. Process 1400 may be performed on the control system 120as illustrated in FIGS. 2 to 4.

In 1401, upon the detection that the first voltage source 210 is servedas the voltage source of the one or more tuning/detuning circuit drivers280-1, 280-2, . . . , 280-n, the processor 132 may determine an outputvoltage of the first voltage source 210 according to configurations ofthe one or more coil arrays 290-1, 290-2, . . . , 290-n.

Since the voltage source of the one or more tuning/detuning circuitdrivers 280-1, 280-2, . . . , 280-n is the first voltage source 210, theone or more corresponding coil arrays 290-1, 290-2, . . . , 290-n may bein the detuning state. The processor 132 may determine the outputvoltage of the first voltage source 210 according to the configurationsof the coil arrays in the detuning state, as illustrated in equation(5). Then, the processor 132 may change the output voltage of the firstvoltage source 210 by adjusting the equivalent resistance value of thevariable resistor 212 (i.e., R_(eq)), as illustrated in equation (4).

In 1402, the processor 132 may determine an expected value of theelectrical signal of the sampling circuit according to at least one ofthe operation status of the RF system 112, the tuning or detuning statusof the local coils, and types of voltage sources set by the one or moretuning/detuning circuit drivers 280-1, 280-2, . . . , 280-n. Theelectrical signal may include the first current, the second current, thefirst voltage, etc. The sampling circuit may include the first currentsampling circuit 131, the second current sampling circuit 135, thevoltage comparison circuit 137, etc. FIG. 6 illustrates some exemplaryoperations for determining the expected value of the electrical signal.

In 1403, the processor 132 may obtain an actual value of the electricalsignal of the sampling circuit. The processor 132 may obtain the actualvalue of the electrical signal by the first current sampling circuit121, the second current sampling circuit 135, the voltage comparisoncircuit 137, etc.

In 1404, the processor 132 may perform fault diagnosis on thetuning/detuning system of the local coils based on the expected value ofthe electrical signal and the actual value of the electrical signal. Insome embodiments, the processor 132 may compare the expected value ofthe electrical signal and the actual value of the electrical signal. Theprocessor 132 may perform the fault diagnosis based on the comparisonresult. Details regarding the fault diagnosis may be found elsewhere inthe present disclosure. See, e.g., FIGS. 7 to 13 and the descriptionsthereof.

It should be noted that the above description of process 1400 is merelyprovided for the purposes of illustration, and not intended to limit thescope of the present disclosure. For persons having ordinary skills inthe art, multiple variations or modifications may be made under theteachings of the present disclosure. However, those variations andmodifications do not depart from the scope of the present disclosure.

Having thus described the basic concepts, it may be rather apparent tothose skilled in the art after reading this detailed disclosure that theforegoing detailed disclosure is intended to be presented by way ofexample only and is not limiting. Various alterations, improvements, andmodifications may occur and are intended to those skilled in the art,though not expressly stated herein. These alterations, improvements, andmodifications are intended to be suggested by this disclosure, and arewithin the spirit and scope of the exemplary embodiments of thisdisclosure.

Moreover, certain terminology has been used to describe embodiments ofthe present disclosure. For example, the terms “one embodiment,” “anembodiment,” and/or “some embodiments” mean that a particular feature,structure or characteristic described in connection with the embodimentis included in at least one embodiment of the present disclosure.Therefore, it is emphasized and should be appreciated that two or morereferences to “an embodiment” or “one embodiment” or “an alternativeembodiment” in various portions of this specification are notnecessarily all referring to the same embodiment. Furthermore, theparticular features, structures or characteristics may be combined assuitable in one or more embodiments of the present disclosure.

Further, it will be appreciated by one skilled in the art, aspects ofthe present disclosure may be illustrated and described herein in any ofa number of patentable classes or context including any new and usefulprocess, machine, manufacture, or composition of matter, or any new anduseful improvement thereof. Accordingly, aspects of the presentdisclosure may be implemented entirely hardware, entirely software(including firmware, resident software, micro-code, etc.) or combiningsoftware and hardware implementation that may all generally be referredto herein as a “block,” “module,” “engine,” “unit,” “component,” or“system.” Furthermore, aspects of the present disclosure may take theform of a computer program product embodied in one or more computerreadable media having computer readable program code embodied thereon.

A computer readable signal medium may include a propagated data signalwith computer readable program code embodied therein, for example, inbaseband or as part of a carrier wave. Such a propagated signal may takeany of a variety of forms, including electro-magnetic, optical, or thelike, or any suitable combination thereof. A computer readable signalmedium may be any computer readable medium that is not a computerreadable storage medium and that may communicate, propagate, ortransport a program for use by or in connection with an instructionexecution system, apparatus, or device. Program code embodied on acomputer readable signal medium may be transmitted using any appropriatemedium, including wireless, wireline, optical fiber cable, RF, or thelike, or any suitable combination of the foregoing.

Computer program code for carrying out operations for aspects of thepresent disclosure may be written in any combination of one or moreprogramming languages, including an object oriented programming languagesuch as Java, Scala, Smalltalk, Eiffel, JADE, Emerald, C++, C#, VB.NET,Python or the like, conventional procedural programming languages, suchas the “C” programming language, Visual Basic, Fortran 2003, Perl, COBOL2002, PHP, ABAP, dynamic programming languages such as Python, Ruby andGroovy, or other programming languages. The program code may executeentirely on the user's computer, partly on the user's computer, as astand-alone software package, partly on the user's computer and partlyon a remote computer or entirely on the remote computer or server. Inthe latter scenario, the remote computer may be connected to the user'scomputer through any type of network, including a local area network(LAN) or a wide area network (WAN), or the connection may be made to anexternal computer (for example, through the Internet using an InternetService Provider) or in a cloud computing environment or offered as aservice such as a Software as a Service (SaaS).

Furthermore, the recited order of processing elements or sequences, orthe use of numbers, letters, or other designations therefore, is notintended to limit the claimed processes and methods to any order exceptas may be specified in the claims. Although the above disclosurediscusses through various examples what is currently considered to be avariety of useful embodiments of the disclosure, it is to be understoodthat such detail is solely for that purpose, and that the appendedclaims are not limited to the disclosed embodiments, but, on thecontrary, are intended to cover modifications and equivalentarrangements that are within the spirit and scope of the disclosedembodiments. For example, although the implementation of variouscomponents described above may be embodied in a hardware device, it mayalso be implemented as a software only solution—e.g., an installation onan existing server or mobile device.

Similarly, it should be appreciated that in the foregoing description ofembodiments of the present disclosure, various features are sometimesgrouped together in a single embodiment, figure, or description thereoffor the purpose of streamlining the disclosure aiding in theunderstanding of one or more of the various inventive embodiments. Thismethod of disclosure, however, is not to be interpreted as reflecting anintention that the claimed subject matter requires more features thanare expressly recited in each claim. Rather, inventive embodiments liein less than all features of a single foregoing disclosed embodiment.

In some embodiments, the numbers expressing quantities of ingredients,properties such as molecular weight, reaction conditions, and so forth,used to describe and claim certain embodiments of the application are tobe understood as being modified in some instances by the term “about,”“approximate,” or “substantially.” For example, “about,” “approximate,”or “substantially” may indicate ±20% variation of the value itdescribes, unless otherwise stated. Accordingly, in some embodiments,the numerical parameters set forth in the written description andattached claims are approximations that may vary depending upon thedesired properties sought to be obtained by a particular embodiment. Insome embodiments, the numerical parameters should be construed in lightof the number of reported significant digits and by applying ordinaryrounding techniques. Notwithstanding that the numerical ranges andparameters setting forth the broad scope of some embodiments of theapplication are approximations, the numerical values set forth in thespecific examples are reported as precisely as practicable.

Each of the patents, patent applications, publications of patentapplications, and other material, such as articles, books,specifications, publications, documents, things, and/or the like,referenced herein is hereby incorporated herein by this reference in itsentirety for all purposes, excepting any prosecution file historyassociated with same, any of same that is inconsistent with or inconflict with the present document, or any of same that may have alimiting affect as to the broadest scope of the claims now or laterassociated with the present document. By way of example, should there beany inconsistency or conflict between the description, definition,and/or the use of a term associated with any of the incorporatedmaterial and that associated with the present document, the description,definition, and/or the use of the term in the present document shallprevail.

In closing, it is to be understood that the embodiments of theapplication disclosed herein are illustrative of the principles of theembodiments of the application. Other modifications that may be employedmay be within the scope of the application. Thus, by way of example, butnot of limitation, alternative configurations of the embodiments of theapplication may be utilized in accordance with the teachings herein.Accordingly, embodiments of the present application are not limited tothat precisely as shown and described.

1-20. (canceled)
 21. A control system comprising: a tuning/detuningsystem including a first voltage source, a second voltage source, andone or more tuning/detuning circuit drivers; and a diagnosis systemincluding a first current sampling circuit and a processor, wherein: thefirst current sampling circuit includes a first analog-to-digitalconverter (ADC), a first operational amplifier, and a first samplingresistor, the processor is configured to diagnose the tuning/detuningsystem.
 22. The control system of claim 21, wherein: the first ADC iselectrically connected to the first operational amplifier, the firstoperational amplifier is electrically connected to the first samplingresistor, the first sampling resistor is electrically connected to thefirst voltage source in series.
 23. The control system of claim 21,wherein the tuning/detuning system includes one or more coil arrayscorresponding to the one or more tuning/detuning circuit drivers, foreach of the one or more coil arrays, the coil array includes one or morefirst diodes; and the one or more first diodes determines a tuning ordetuning status of the coil array.
 24. The control system of claim 21,wherein the first voltage source, including a first output end, isconfigured to provide a power supply that outputs a constant current;and the second voltage source, including a second output end, isconfigured to output a constant negative voltage.
 25. The control systemof claim 23, wherein for each of the one or more tuning/detuning circuitdrivers, the tuning/detuning circuit includes a first input end, asecond input end, a third output end, and a first control end; the firstinput end, electrically connected to the first output end of the firstvoltage source, serves as a positive power supply input port and isconfigured to output the constant current; the second input end,electrically connected to the second output end of the second voltagesource, serves as a negative power supply input port and is configuredto output the constant negative voltage; and the third output end,electrically connected to a corresponding coil array, is configured tooutput the constant current or the constant negative voltage thatdetermines a conduction status of the one or more first diodes of thecorresponding coil array.
 26. The control system of claim 41, wherein:the first current sampling circuit is configured to obtain a firstcurrent outputted by the first voltage source; and the processor isconfigured to diagnose the tuning/detuning system based on the firstcurrent.
 27. The control system of claim 26, wherein: the diagnosiscircuit system includes a first switch module and one or more dummyloads corresponding to the one or more tuning/detuning circuit drivers,wherein: each dummy load of the one or more dummy loads, including oneor more second diodes, is electrically connected to a correspondingtuning/detuning circuit in parallel, the one or more dummy loads areelectrically connected to a common connecting end in parallel, the firstswitch module is electrically connected to ground, electricallyconnected to the common connecting end, and operatively connected to theprocessor, and the processor is configured to cause the first switchmodule to turn on or turn off, and to diagnose the tuning/detuningsystem based on the first current.
 28. The control system of claim 27,wherein the diagnosis circuit system includes a second current samplingcircuit, wherein the second current sampling circuit, operativelyconnected to the processor, is configured to obtain a second current ofthe common connecting end, and the processor is configured to diagnosethe tuning/detuning system based on the second current.
 29. The controlsystem of claim 28, wherein the second current sampling circuit includesa second ADC, a second operational amplifier, and a second resistor,wherein: the second ADC is electrically connected to the secondoperational amplifier in series and operatively connected to theprocessor, the second operational amplifier is electrically connected tothe second resistor in parallel, and the second resistor is electricallyconnected to the first switch module in series and electricallyconnected to at least one of the one or more dummy loads in series. 30.The control system of claim 21, wherein: the diagnosis circuit systemincludes a third resistor, a second switch module, and a voltagecomparison circuit, wherein: the third resistor is electricallyconnected to the second switch module in parallel, a first end of thethird resistor is electrically connected to the second voltage source, asecond end of the third resistor is electrically connected to at leastone of the one or more tuning/detuning circuit drivers, the voltagecomparison circuit is electrically connected to the second end of thethird resistor and operatively connected to the processor, the voltagecomparison circuit is configured to obtain a first voltage of the secondend of the third resistor and compare the first voltage with a referencevoltage, and the processor is configured to diagnose the tuning/detuningsystem based on the comparison between the first voltage and thereference voltage.
 31. The control system of claim 30, wherein: thediagnosis circuit system includes a third switch module, wherein thethird switch module is electrically connected to the second voltagesource in series, electrically connected to the third resistor inseries, and operatively connected to the processor; and the processor isconfigured to cause the third switch module to turn on or turn off. 32.The control system of claim 24, wherein: the first voltage sourceincludes a DC-DC controller, a fourth resistor, and a variable resistor,wherein: the DC-DC controller is electrically connected to the firstoutput end of the first voltage source though an output end of the DC-DCcontroller, the fourth resistor is electrically connected to ground andelectrically connected to the DC-DC controller through a feedback inputof the DC-DC controller, the variable resistor is electrically connectedto the fourth resistor, electrically connected to the first output endof the first voltage source, and operatively connected to the processor,and the processor is configured to cause an equivalent resistance valueof the variable resistor to change.
 33. A method, implemented on thecontrol system including a tuning/detuning system including a firstvoltage source, a second voltage source, one or more coil arrays, andone or more tuning/detuning circuit drivers; and a diagnosis system, themethod comprising: upon a detection that a radio frequency system isidle and the one or more coil arrays are electrically disconnected fromthe radio frequency system, making the second voltage source as thevoltage source of the one or more tuning/detuning circuit drivers anddetermining a second expected value of a first voltage; determining anactual value of the first voltage; and determining whether the actualvalue of the first voltage is greater than the second expected value ofthe first voltage.
 34. The method of claim 33, further comprising:determining that the actual value of the first voltage is greater thanthe second expected value of the first voltage; and in response to adetermination that the actual value of the first voltage is greater thanthe second expected value of the first voltage, determining that noshort circuit exists in the one or more tuning/detuning circuit drivers.35. The method of claim 33, further comprising: determining that theactual value of the first voltage is not greater than the secondexpected value of the first voltage; and in response to a determinationthat the actual value of the first voltage is not greater than thesecond expected value of the first voltage, determining that a shortcircuit exists in at least one of the one or more tuning/detuningcircuit drivers.
 36. The method of claim 33, further comprising:changing a type of the voltage source of one of the one or moretuning/detuning circuit drivers to the first voltage source; determininga second actual value of a first current outputted by the first voltagesource; and determining whether the second actual value of the firstcurrent increases by a predetermined increment.
 37. The method of claim36, further comprising: determining that the second actual value of thefirst current fails to increase by the predetermined increment; and inresponse to a determination that the second actual value of the firstcurrent fails to increase by the predetermined increment, determiningthat an open circuit exists in the one or more tuning/detuning circuitdrivers.
 38. The method of claim 36, further comprising: determiningthat the second actual value of the first current increases by thepredetermined increment; in response to a determination that the secondactual value of the first current increases by the predeterminedincrement, determining an actual value of a second current obtained bythe diagnosis circuit system; and determining whether the actual valueof the second current increases by the predetermined increment.
 39. Themethod of claim 38, further comprising: determining that the actualvalue of the second current increases by the predetermined increment;and in response to a determination that the actual value of the secondcurrent increases by the predetermined increment, determining that noshort circuit exists at the third output end of the tuning/detuningcircuit driver.
 40. A method, implemented on a control system includinga tuning/detuning system including a first voltage source, a secondvoltage source, one or more coil arrays, and one or more tuning/detuningcircuit drivers; and a diagnosis system, the method comprising: upon adetection that the first voltage source as a voltage source of the oneor more tuning/detuning circuit drivers, determining an output voltageof the first voltage source according to configurations of the one ormore coil arrays; determining an expected value of an electrical signalaccording to at least one of an operation status of a radio frequencysystem, a tuning or detuning status of the one or more coil arrays, andtypes of voltage sources of the one or more tuning/detuning circuitdrivers; determining an actual value of the electrical signal; andperforming fault diagnosis on the tuning/detuning system based on theexpected value of the electrical signal and the actual value of theelectrical signal.